At last year's trade deadline, fans implored San Francisco Giants general manager Brian Sabean to bolster the offense.

Sabean traded for starter Jake Peavy five days before the deadline, but he didn't make any more trades to improve the offense. But as we know, that worked out just fine for the World Series champions.

However, the Giants are in the midst of another tough summer, and a splashy acquisition might be the way to turn the tables. San Francisco's pitching depth is stellar, but it lacks a proven, healthy top-of-the-line starter to complement Madison Bumgarner.

In addition, injuries to the outfield have also plagued the team, and the Giants are short on left-handed relief help.

With all of these holes, the Giants are almost certain to make a trade at some point. Which targets should they be zeroing in on?

Jon Niese, New York Mets, SP

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The Giants have eight potential starters, but they don't have five reliable ones.

Between Madison Bumgarner, Chris Heston, Ryan Vogelsong, Tim Hudson, Tim Lincecum, Matt Cain and Jake Peavy, the Giants have a plethora of players who could start. However, not all of these players have proved to be reliable.

Lincecum, Hudson, Cain and Peavy have all been on the disabled list. Cain and Peavy have done well since returning, but whether they can keep up their consistent pace and stay healthy remains to be seen. Peavy tailed off in the playoffs last year, and Cain hasn't pitched well for a full season since 2012.

Only Bumgarner and Heston have consistently performed well, and an up-and-down Vogelsong's numbers look decent. The Giants rotation could benefit from someone to help out in the short term and, perhaps more importantly, in the long term.

With Hudson, Lincecum and Vogelsong on the verge of becoming free agents, the Giants need someone to stabilize their rotation for the next few years.

Jon Niese could fill that role.

He has a 3.90 ERA this season and has consistently performed around that level throughout his career. He has posted a sub-4.00 ERA every year since 2012. He's not a star, but the Giants just need consistency right now.

Moving to AT&T Park could help Niese even more and allow him to thrive as a middle-of-the-rotation workhorse. He could fill this role for two years, as his contract doesn't expire until the end of 2016. With two years on the team, Niese could also be swayed to stay in San Francisco like many trade acquisitions do.

Niese isn't a high-profile name, so he wouldn't cost a lot. However, like Peavy last year, he could pay dividends as an under-the-radar acquisition.

Mat Latos, SP, Miami Marlins

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Mat Latos, on the contrary to Jon Niese, has not performed up to par with his usual standard this year.

Latos has pitched horribly this year, as his 4.90 ERA is not at all up to snuff with his career ERA of 3.47. He has not been the same pitcher, which means that the Giants could buy low and reap the benefits.

Why should the Giants trust that he'll turn his performance around? First of all, his ERA was below 3.50 for the last five years, so historically, Latos has been consistent.

Second, he has started to improve lately. He threw a one-hitter over seven innings in his most recent start against the Cubs, and since the start of June, his ERA is a solid 3.31.

If the Giants make a trade soon, they could avoid giving up a top prospect and still receive a potential top-flight starter in return. Even if not, they can trust that Latos will stabilize the rotation on the back end.

He's only signed through the end of this year, but pitching at AT&T Park could be enticing to Latos in the long term, despite previous turmoil with the Giants. Even if Latos doesn't re-sign, he could be acquired at a cheap price and would be well worth a trade.

Gerardo Parra, CF, Milwaukee Brewers

Hunter Pence is a five-tool player who provides a spark in the middle of the lineup, and Nori Aoki gets things going from the top of the order.

Generally, Angel Pagan is a quality player who can hit anywhere in the lineup, but that hasn't been the case lately.

He has struggled mightily this whole season, and judging from his injury history, including a hamstring injury that caused him to miss most of 2013 and a season-ending back injury in 2014, he's not a sure bet to stay healthy throughout the season.

The Giants, according to Andrew Baggarly of the San Jose Mercury News, have had interest in him for a long time. And there's good reason for that interest.

Parra has had a phenomenal season for the Milwaukee Brewers, posting an .832 OPS with eight home runs and 26 RBI. He has played center and left field for the Brewers, and he could play anywhere in the outfield for the Giants.

Since he's not a household name, he wouldn't cost a fortune. He will likely cost a pair of mid-tier prospects, but the Brewers will probably be desperate to deal him since he's an impending free agent.

But if the Giants trade for him, he could still re-sign with the team. The Giants have had luck re-signing outfielders whom they've traded for, such as Pagan and Pence.

Pagan has played well in his four-year tenure with the Giants, but his .610 OPS this year isn't cutting it. The Giants need to make a trade if they want a full-time center fielder who can solidify the middle of the lineup, and Parra is a perfect fit.

Will Smith, RP, Milwaukee Brewers

Morry Gash/Associated Press

The Giants have had a great bullpen over the last few years, but this season, they've had trouble finishing games.

San Francisco ranks a mediocre 18th in bullpen ERA, and it lacks left-handed relievers to take the load off Javier Lopez. About a week ago, it called up Josh Osich, who has thrived lately, but it could still use help balancing out the bullpen.

That's where Will Smith comes in.

Smith might be best known for his eight-game suspension earlier this year, but outside of that, he's been a dominant reliever.

He has a 1.67 ERA and has shut down both lefties and righties. Opponents have a .535 OPS against him at hitter-friendly Miller Park, where he has somehow thrived.

Since he's not a household name and has been average over the course of his career, he would be relatively cheap. However, much like with Lopez, who was traded for unknowns Joe Martinez and John Bowker in 2010, trading for Smith could pay dividends.